P289 Hyperoxaluria in patients after ileocolic resection

Abstract Background Oxaluria is one of the risk factors for developing urolithiasis and oxalate nephropathy, which may lead to renal failure. Patients with Crohn's disease (CD) who underwent an ileocolic (IC) resection are at increased risk. The aim of the study is to determine the incidence of hyperoxaluria in these patients in comparison to CD patients with IC involvement without the resection. Methods Patients with CD of age over 18 years after IC resection were included into the study and patients with IC involvement without resection were included as a control group. Exclusion criteria were concomitant citrate treatment, severe chronic kidney disease (G4-5 KDIGO with GFR <30ml/min/1,73 m2) and patients with more than two intestinal resections, with colectomy or with short bowel syndrome. Patients filled out a questionnaire form, a blood sample and fresh urine sample were taken, abdominal ultrasonography for assessment of kidneys and gallbladder was performed and finally, patients collected urine for 24 hours for examination of oxaluria and citraturia. Oxaluria over 0,6 mmol/24 hours and citraturia under 1,6 mmol/24 hours were considered significantly pathological. Results 40 patients were included in the study until now. There were 45% after IC resection, 57.5% were female (77.8% in the resection group and 40.9% in the control group), mean age was 41,5 years +/-13,1. 7 patients were receiving corticosteroid treatment, 26 had immunosuppressants and 4 patients had biologics. Hyperoxaluria has been detected in 27.5% (of all patients), in 22% in the resection group and in 31.8% in the control group (p=0,34). Hypocitraturia has been found in 32.5%, in 38.9% in the resection group and 27.3% in the control group (p=0,41). No patient with urolithiasis and one with cholecystolithiasis was detected with ultrasonography and one patient had urolithiasis in medical history. Conclusion Hyperoxaluria was detected in 27.5% of patients and there was no significant difference between the groups with and without IC resection. Hypocitraturia was detected in 32.5% with nonsignificant predominance in the resection group. Recruitment of patients is still going on, as now we can't determine the role of routine testing for hyperoxaluria and hypocitraturia in daily practice.